Hydraulic control apparatus

ABSTRACT

A control apparatus by which the ring rail of a twisting machine, and also the hydraulic, pump driven motor raising and lowering the same, are automatically moved to an end position if an interruption of the electric power supply to the pump occurs in an intermediate position of the ring rail. In this event, a spring biassed electromagnetic control valve, when deenergized, causes the flow of pressure fluid from a pressure accumulator to the hydraulic motor which is driven to complete the started reciprocating stroke.

[451 Mar. 28, 1972 [56] References Cited UNITED STATES PATENTS 2,595,248 5/1952 Greer et 2,396,984

Ernst Bauch, Brodesholm; Bruno Eigenwald, Neumuenster, both of Germany United States Patent Bauch etal.

[54] HYDRAULIC CONTROL APPARATUS [72] Inventors:

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| l I I mw lwlrkllb 111i {Qum HYDRAULIC CONTROL APPARATUS BACKGROUND OF THE INVENTION lt is known to operate the ring rails of twisting machines by hydraulic motors driven by pumps rotated by electromotors. ln the event that the electric power is interrupted, particularly accidentally, the entire twisting machine stops, and the ring rail stops in a position reached at the moment of interruption of the electric power supply. Due to inertia rotation, an annular bulge is wound on the cops due to the stopping of the reciprocation, and the cops cannot be used, unless the annular thread bulge -is manually removed.

lt is one object of the invention to overcome this disadvantage, and provide an apparatus which assures that the reciprocating ring rail of a twisting machine, always stops in an end position, irrespective of the moment at which an interruption of the power supply occurs.

It is a more general object of the invention to move a reciprocating element to an end position if the drive means reciprocating the element are stopped due to power failure.

Another object of the invention, is to prevent the forming of an annular bulge of thread on a cop or bobbin in the event that the machine on which the cops are wound, stops due to a power failure.

SUMMARY OF THE INVENTION The objects of the invention are obtained by the use of a pressure accumulator which, in the event of a power failure, supplies pressure fluid to the hydraulic motor operating the ring rail so that the motor can complete its stroke.

An embodiment of the invention comprises a hydraulic motor for operating a reciprocable element, particularly a ring rail; a pump; an accumulator for a pressure fluid; and control valve means including electromagnetic means for holding the control valve means in a normal position in which the pump operates the hydraulic motor. The control valve means is bassed to assume a control position when the electromagnetic means are de-energized upon an interruption of the electric power. ln the control position, the control valve means connect the accumulator with the motor so that the motor is moved by pressure fluid from the accumulator with the element, for example the ring rail, to an end position if the electric power was interrupted in an intermediate position of the hydraulic motor and the ring rail.

Pressure responsive means communicating with the accumulator are provided for energizing the electromagnetic means at a predetermined pressure. Consequently, the control valve means are moved back to the normal position by the electromagnetic means when the pressure fluid, pumped by the pump into the accumulator after electric power has been again supplied to the pump, reaches the predetermined pressure.

The accumulator can operate with compressed air, however, it is preferred to connect the accumulator with the pressure conduit of the pump so that the accumulator is filled with pressure fluid from the pump. The pressure responsive means is operative only while the machine is started again after an interruption of the electric power, and closes when the accumulator has reached the required pressure.

Preferably two control valves, each electromagnetically operated, are provided. A first control valve connects the pump with the reversing valve of the hydraulic motor and is bassed to assume a control position for connecting the accumulator with the pump and with a second control valve which is closed during normal operation, and is bassed to a control position for connecting the first control valve and the accumulator with the hydraulic motor.

lt is advantageous to combine several control valves in a single control unit.

The apparatus is particularly suitable for twisting machines on which threads consisting of a synthetic material are stretched, twisted, and wound up.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional ob jects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. l is a schematic view illustrating the hydraulic control apparatus of the invention; and

FIG. 2 is a schematic and partly diagrammatic view illustrat ing the control apparatus of FIG. 1 in greater detail, and also showing the electrical connections required for operating the valves of the apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT A hydraulic pump 1, which is driven by an electric motor and only schematically indicated, sucks a pressure fluid from an open receptacle 3 by means of ari inlet tube 2. The pressure fluid is pumped through a pump conduit 4 and a first control valve 5 in the normal position illustrated in the drawing, through a conduit 6 into reversing valve means 7 from which the fluid is discharged through a conduit 8 into the variable chamber 9 formed by a piston 11 in the cylinder 10 of a hydraulic motor whose other variable chamber l2 is connected by a conduit 13 to the reversing valve means 7 and to a discharge conduit 14 ending in the open receptacle 3 so that in the normal position of control valve 5, piston ll is driven upward, while upon reversal of' reversing valve 7, the fluid is pumped into chamber l2 and discharged from chamber 9 so that the piston 11 moves downward. Piston 11 is secured to a belt 7l passing over pulleys 70, and being connected with the ring rail 22 carrying spindles 22a on which cops or bobbins 22b rotate. When piston 1l is moved upward to an end position, ring rail 22 is in the lower end position, and when piston l 1 is moved downward to the end position, ring rail 22 is in its upper end position. If the electric power for driving pump l is interrupted in an intermediate position of piston 11 and ring rail 22, the same stops in the respective intermediate position, and since the cops 22b do not reciprocate in axial direction, annular bulges would be wound on the cops, which is prevented by the apparatus of the invention.

FIG. 2 illustrates the construction of the reversing valve means 7 and the electric control of the same. A source of electrical power having a voltage of 220 volts is connected to the lines 40 and 50. Line 50 is connected with the electromagnetic means 25a, 25b of reversing valve 7, and line 40, which has a switch 35, is connected to a switching device 60 which has contacts 27a and 27b cooperating with adjustable stops 26a and 26h so that in the end positions of piston l1, current is supplied either through line 42 or through line 43 which are respectively connected with the electromagnetic means 25a and 2Sb. When the electric power supply is interrupted, for example by opening switch 35, springs 23a and 23b place the valve slide 24 in a central position so that the conduits 8 and 13 are closed and no pressure fluid can flow from conduit 6 into the hydraulic motor l0.

When switch 35 is closed, the electromagnetic winding 25a is energized and moves slide 24 against the action of a spring downward so that pressure fluid, such as oil, can flow through conduit 6 and conduit 8 into chamber 9, and piston l1 is moved upward, while the pressure fluid in chamber 12 flows through conduits 13, 14a, and 14 to the receptacle 3.

When piston 11 arrives in the end position, winding 25h is energized, and slide 24 is moved upward so that pressure fluid flows through conduits 6 and 13 into chamber l2 and moves the same downward, while the pressure fluid in chamber 9 is discharged through conduits 8, ll4b and 14 into receptacle 3.

When switch 35 is closed, winding 25a or winding 25b is energized, depending on whichcontact 27a or 27b was last effective.

Referring again mainly to FIG. 1, a first control valve is schematically shown, which is held in the illustrated normal position by energized electromagnetic means 30b, which will be described in greater detail with reference to FIG. 2. In the normal position, the pump conduit 4 is connected by control valve 5 with conduit 6, as indicated by an arrow. A spring 28 urges control valve 5 to a control position in which pump conduit 4, and connecting conduit 17 are connected with a conduit in which a pressure responsive means 31 is provided. A pressure accumulator 16 is connected with conduit 15, and the pressure responsive means 31 responds to the pressure of accumulator 16.

The connecting conduit 17 is in the normal illustrated condition of the second control valve 18, disconnected froma conduit 19 which ends in conduit 8. A second conduit 20, connected with conduit 13, is also closed by the control valve 18 in the illustrated normal position of FIG. 2. Control valve 18 is held in the illustrated normal position by an electromagnetic winding 32, and is urged by a spring 34 to a control position in which connecting conduit 17 is connected with conduit 19, and conduit 20 is connected with a discharge conduit 21 opening into receptacle 3.

Referring to FIG. 2, the control valves 5 and 18 are connected to the voltage source and switch 35 by lines 44 and 45. When the electric power is interrupted, for example by opening switch 35, the spring 28 of valve 5 urges piston 29 to the upper position, and pressure fluid in accumulator 16 flows through conduits 15, 4 and 17 to the control valve 18. Since the motor of pump 1 is disconnected from the voltage, the

pump stops. The connection between the pump and conduit 6 is interrupted.

When switch 35 is closed, and the apparatus starts again, winding 30a is energized, and piston 29 is urged downward by the same against spring 28. Pump 1 pumps the pressure fluid through conduits 4 and 15 to accumulator 16. The pressure in the accumulator 16 is effective to control the pressure responsive means 31 which is a manometer, so that the same operates switching means, not shown, at a predetermined pressure, disconnecting winding 30a and connecting winding 30h with the power source. Piston 29 is moved downward against the action of spring 29, closes conduit 15, and permits 'the pressure fluid to flow through conduits 4 and 6 to the reversing valve means 7.

When switch 35 is closed, the winding 32 of control valve 18 is continuously energized, and piston 33 is pushed to the normal lower position blocking flow through conduit 17 to conduit 20, and blocking also discharge conduit 19, 21.

When the electric power is interrupted, spring 34 urges slide 33 upward to the control position, so that pressure fluid can flow through conduits 17 and 20 into chamber 9 of the hydraulic motor l0.` The pressure fluid in chamber 12 flows through conduits 13, 20 and 21 to receptacle 3.

In the normal positions of control valves 5 and 18, pressure oil is pumped by pump 1, control valve 5, reversing valve means 7, into the hydraulic motor l0 which operates the spindle rail 22 to reciprocate the same. If the electric power is interrupted while piston 1l is in an intermediate position, pump 1 stops, control valve 5 is moved to the-control position connecting accumulator 16 with the respective chamber of hydraulic motor 10 so that piston 1l continues its movement to the end position of the started stroke thereof. The fluid flows from connecting conduit 17 and through control valve 18 which is shifted by spring 34 to the control position connecting conduit 17 through conduit 19 with conduit 8 and chamber 9, and chamber 12 with conduit 20 and the receptacle 3.

It will be understood that each of the elements described above, or two or more together, may also find a useful applica tion in other types of hydraulic control apparatus for operating a reciprocable ring rail of a twisting machine differing from the types described above.

While the invention has been illustrated and described as embodied in a control apparatus for moving the ring rail of a twisting machine to an end position when the power supply was interrupted in an intermediate position of the reciprocating ring rail, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in'any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

We claim:

1. Hydraulic control apparatus comprising a hydraulic motor for operating a reciprocable element, particularly a ring rail; a pump having a pressure conduit, and including electric drive means; an accumulator for a pressure fluid; control valve means including electromagnetic means for holding said control valve means in a normal position in which fluid pressurized by s'aid pump operates said hydraulic motor, said control valve means being biassed to assume a control position when said electromagnetic means are de-energized upon an interruption of the electric power, said control valve means in said control position connecting said accumulator with said motor and said pressure conduit with said accumulator so that said motor is moved by pressure fluid from said accumulator with said element to an end position if the electric power was interrupted in an intermediate position of said motor and element; and pressure responsive means communicating with said accumulator for energizing said electromagnetic means at a predetermined pressure whereby said control valve means are moved back to said normal position by said electromagnetic means when the pressure fluid, 'de-energized by said pump into said accumulator after electric power has again been supplied to said pump, reaches said predetermined pressure. 1

2. Hydraulic control apparatus comprising a hydraulic motor for operating a reciprocable element, particularly a ring rail; a pump; reversing valve means for connecting said pump with said motor; an accumulator for a pressure fluid; a first control valve having a normal position connecting said pump with said reversing valve means, and being biassed to a control position for connecting said accumulator with said pump, said first control valve having first electromagnetic' means for placing the same in said normal position, when energized; and a second control valve having a normal closed position, and being biassed to a control position for connecting said first control valve in said control position of the samewith said hydraulic motor, said second control valve having second electromagnetic means forplacing the same in said normal closed position so that when the electric power is interrupted in an intermediate position of said motor and element and said first and second biassed control valves move to said control positions, said motor is connected by said first and second control valves in said control positions with said accumulator and is moved with said element to an end position.

3. Control apparatus as claimed in claim 2 wherein said pump includes an electric drive means; comprisinga pressure responsive means communicating with said accumulator and electrically connected with said first electromagnetic means for causing energization of said tirst electromagnetic means at a predetermined pressure whereby, when electric power is again supplied after an interruption and said pump pumps pressure fluid through said first control valve in said control position, the pressure in said accumulator is increased until said predetermined pressure is reached and said pressure responsive means causes energization of said first electromagnetic means and movement of said first control valve to said normal position; and wherein said second electromagnetic means moves said second control valve to said normal position thereof when electric power is again supplied.

4. Control apparatus as claimed in claim 2 wherein each said control valve includes a spring for moving the same to said control position thereof.

5. Control apparatus as claimed in claim 2 wherein each said control valve includes a valve slide movable between said normal and control positions, and a spring biassing the respective valve slide to said control position.

6. Control apparatus as claimed in claim 2 wherein said hydraulic motor has a cylinder, and a piston forming in said cylinder first and second variable chambers and being connected with said element for reciprocating the same; a receptacle from which said pump sucks the pressure fluid; first and second conduits connecting said reversing valve means with said first and second chambers, respectively; a third conduit connecting said reversing valve means with said first control valve in said normal position; a fourth conduit connecting said reversing valve means with said receptacle; first and second control conduits connecting said first and second chambers with said second control valve; a discharge conduit connecting said second control valve with said receptacle; a connecting conduit connecting said first control valve with said second control valve; and a pump conduit connecting said pump with said first control valve whereby when said control valves are in said control positions, pressure fluid flows from said accumulator through said first control valve, said connecting conduit, said second control valve, and said first control conduit into said first chamber while pressure fluid is discharged from said second chamber through said second control conduit, said second control valve, and said discharge conduit into said receptacle, while in said normal positions of said control valves, said pump pumps fluid through said pump conduit, first control valve, and said third conduit tov said reversing valve means.

7. Control apparatus as claimed in claim 6 wherein said pump includes an electric drive means; comprising a pressure responsive means communicating with said accumulator and electrically connected with said first electromagnetic means for causing energization of said first electromagnetic means at a predetermined pressure whereby, when electric power is again supplied after an interruption and said pump pumps pressure fluid through said pump conduit and said first control valve in said control position, the pressure in said accumulator is increased until said predetermined pressure is reached and said pressure responsive means causes energization of said first electromagnetic means and movement of said first control valve to said nonnal position; and wherein said second electromagnetic means moves said second control valve to said normal position thereof when electric power is again supplied.

8. Control apparatus as claimed in claim 7 wherein each said control valve includes a valve slide movable between said normal and control positions, and a spring biassing the respective valve slide to said control position. 

1. Hydraulic control apparatus comprising a hydraulic motor for operating a reciprocable element, particularly a ring rail; a pump having a pressure conduit, and including electric drive means; an accumulator for a pressure fluid; control valve means including electromagnetic means for holding said control valve means in a normal position in which fluid pressurized by said pump operates said hydraulic motor, said control valve means being biassed to assume a control position when said electromagnetic means are de-energized upon an interruption of the electric power, said control valve means in said control position connecting said accumulator with said motor and said pressure conduit with said accumulator so that said motor is moved by pressure fluid from said accumulator with said element to an end position if the electric power was interrupted in an intermediate position of said motor and element; and pressure responsive means communicating with said accumulator for energizing said electromagnetic means at a predetermined pressure whereby said control valve means are moved back to said normal position by said electromagnetic means when the pressure fluid, pumped by said pump into said accumulator after electric power has again been supplied to said pump, reaches said predetermined pressure.
 2. Hydraulic control apparatus comprising a hydraulic motor for operating a reciprocable element, particularly a ring rail; a pump; reversing valve means for connecting said pump with said motor; an accumulator for a pressure fluid; a first control valve having a normal position connecting said pump with said reversing valve means, and being biassed to a control position for connecting said accumulator with said pump, said first control valve having first electromagnEtic means for placing the same in said normal position, when energized; and a second control valve having a normal closed position, and being biassed to a control position for connecting said first control valve in said control position of the same with said hydraulic motor, said second control valve having second electromagnetic means for placing the same in said normal closed position so that when the electric power is interrupted in an intermediate position of said motor and element and said first and second biassed control valves move to said control positions, said motor is connected by said first and second control valves in said control positions with said accumulator and is moved with said element to an end position.
 3. Control apparatus as claimed in claim 2 wherein said pump includes an electric drive means; comprising a pressure responsive means communicating with said accumulator and electrically connected with said first electromagnetic means for causing energization of said first electromagnetic means at a predetermined pressure whereby, when electric power is again supplied after an interruption and said pump pumps pressure fluid through said first control valve in said control position, the pressure in said accumulator is increased until said predetermined pressure is reached and said pressure responsive means causes energization of said first electromagnetic means and movement of said first control valve to said normal position; and wherein said second electromagnetic means moves said second control valve to said normal position thereof when electric power is again supplied.
 4. Control apparatus as claimed in claim 2 wherein each said control valve includes a spring for moving the same to said control position thereof.
 5. Control apparatus as claimed in claim 2 wherein each said control valve includes a valve slide movable between said normal and control positions, and a spring biassing the respective valve slide to said control position.
 6. Control apparatus as claimed in claim 2 wherein said hydraulic motor has a cylinder, and a piston forming in said cylinder first and second variable chambers and being connected with said element for reciprocating the same; a receptacle from which said pump sucks the pressure fluid; first and second conduits connecting said reversing valve means with said first and second chambers, respectively; a third conduit connecting said reversing valve means with said first control valve in said normal position; a fourth conduit connecting said reversing valve means with said receptacle; first and second control conduits connecting said first and second chambers with said second control valve; a discharge conduit connecting said second control valve with said receptacle; a connecting conduit connecting said first control valve with said second control valve; and a pump conduit connecting said pump with said first control valve whereby when said control valves are in said control positions, pressure fluid flows from said accumulator through said first control valve, said connecting conduit, said second control valve, and said first control conduit into said first chamber while pressure fluid is discharged from said second chamber through said second control conduit, said second control valve, and said discharge conduit into said receptacle, while in said normal positions of said control valves, said pump pumps fluid through said pump conduit, first control valve, and said third conduit to said reversing valve means.
 7. Control apparatus as claimed in claim 6 wherein said pump includes an electric drive means; comprising a pressure responsive means communicating with said accumulator and electrically connected with said first electromagnetic means for causing energization of said first electromagnetic means at a predetermined pressure whereby, when electric power is again supplied after an interruption and said pump pumps pressure fluid through said pump conduit and said first control valve in said control posItion, the pressure in said accumulator is increased until said predetermined pressure is reached and said pressure responsive means causes energization of said first electromagnetic means and movement of said first control valve to said normal position; and wherein said second electromagnetic means moves said second control valve to said normal position thereof when electric power is again supplied.
 8. Control apparatus as claimed in claim 7 wherein each said control valve includes a valve slide movable between said normal and control positions, and a spring biassing the respective valve slide to said control position. 